1. Field of the Invention
The present invention relates to an apparatus of manufacturing a semiconductor device, and more particularly, to a transfer chamber for a cluster system of manufacturing a semiconductor device.
2. Discussion of the Related Art
Due to rapid development in information technology, display devices have evolved to process and display increasingly large amounts of information. Flat panel display technologies have been recently conceived and developed for display devices having small thickness, light weight, and low power consumption. Among these technologies, a liquid crystal display (LCD) device has been spotlight as a substitution for a cathode ray tube (CRT) because of its superior resolution, color image display, and image quality, and is already widely used for notebook computers, desktop monitors, and other application.
The LCD device may include a plurality of pixels, in each of which a switching element may be formed to independently control the pixel. This LCD device is commonly referred to as an active matrix liquid crystal display (AMLCD) device. A thin film transistor may be used as the switching element, and the LCD device including the thin film transistor is referred to as a thin film transistor (TFT) LCD device.
The TFT LCD device includes two substrates on which elements, such as electric field forming electrodes and thin film transistors, are formed as thin films. The elements are formed by repeatedly depositing a thin film and patterning the thin film through a photolithography process. The photolithography process includes a light exposing process for selectively exposing or covering the thin film, an etching process for selectively removing the thin film to have a predetermined shape, and a cleaning process for eliminating residues, wherein the cleaning process includes washing and drying.
Each process is performed within a processing chamber where the optimum conditions are made for the corresponding process. Recently, to deal with a plurality of substrates in a short time, a cluster system is used. The cluster system includes processing chambers for carrying out the above processes and a transfer chamber for keeping the substrates and transporting or sending back the substrates.
The cluster system is also used for a manufacturing process of a semiconductor device, which includes repeated processes of depositing a thin film on a semiconductor substrate such as silicon wafer, patterning the thin film through the photolithography process and cleaning the patterned thin film. Here, objects treated within the cluster system may be referred to as substrates.
FIG. 1 is a schematic view of a related art cluster system. In FIG. 1, the cluster system includes a storing part 10, a loadlock chamber 20, a plurality of processing chambers 42, 44, 46 and 48, a preheating chamber 50, and a transfer chamber 30. In the storing part 10, a plurality of substrates (not shown) are kept. The loadlock chamber 20 has at least one slot to load the substrates temporarily. In the processing chambers 42, 44, 46 and 48, treatments for the substrates are performed. Before the substrates are loaded in one of the processing chambers 42, 44, 46 and 48 and are dealt with, the substrates are preheated in the preheating chamber 50. The transfer chamber 30 is connected to the loadlock chamber 20, the plurality of processing chambers 42, 44, 46 and 48, and the preheating chamber 50.
The transfer chamber 30 serves as a temporary storing place or passage that the substrates commonly pass through when the plurality of untreated substrates in the storing part 10 are dealt with through the loadlock chamber 20, the preheating chamber 50 and the processing chambers 42, 44, 46 and 48, respectively, and then are returned.
FIG. 2 illustrates the transfer chamber for the related art cluster system. In FIG. 2, the transfer chamber 30 includes a body 32 and a cover 38. The body 32 has an opening for combining with the cover 38. Loadlock chamber connecting portions 34 are formed at one side of the body 32, and a plurality of processing chamber connecting portions 35 are formed at other sides of the body 32, respectively.
The loadlock chamber connecting portions 34 and the plurality of processing chamber connecting portions 35 are connected to an inner space 36 of the body 35. Thus, a robot (not shown), which is equipped in the inner space 36, transports the substrates into the storing part 10, the loadlock chamber 20, and the processing chambers 42, 44, 46 and 48 of FIG. 1, and returns the substrates.
A size of the transfer chamber 30 as the temporary storing place or passage of the substrate depends on a size of the substrate. A substrate for a latest fifth generation LCD device has a size of about 1,100 mm×1,300 mm. According as the LCD device grows larger, a substrate for a sixth generation LCD device may have a size of about 1,500 mm×1,800 mm to 1,800 mm×2,000 mm. Therefore, the transfer chamber may have a maximum diagonal of about 4,200 mm.
However, since the transfer chamber is made of aluminum or stainless steel, it is difficult to manufacture the large transfer chamber as one body with other chambers. In addition, although the large transfer chamber is manufactured as one body with other chambers, there are disadvantages that manufacturing costs is increased and it is not easy to transport the chambers.